1. Field of the Invention
This invention relates to portable compression testing of polyurethane or similar roof insulating and building materials to determine the yield point of a known size core sample in the field.
2. Description of the Background Art
In building construction, it is common practice in the industry to use spray foam to insulate and coat roofs. This spray foam is applied to the roof in a liquid state and expands to set up as foam very quickly. The end product is a porous cellulose foam that must meet certain yield point guidelines established by the industry. These guidelines are set to protect the integrity of the roof from events such as hail, wind, foot traffic, equipment loading, and other common occurrences.
In addition, the material is to be tested from a sample that has been sprayed at the point of application (i.e. on the roof). This will take into account the liquid foam mixture used for the specific application and environmental conditions existing for the specific location.
Presently, the only method of testing foam being applied at a specific site is to spray a sample on site and send these samples to a laboratory for testing. These tests normally take anywhere from 1 to 5 days. Common practice is to coat the entire roof or application area before the test results are returned. This saves time which is very valuable in the construction industry. However, if the test results show that the foam failed to meet certain guidelines, then all of the foam applied must be removed and the roof must be redone. This is a very costly procedure that wastes both time and money.
Currently, there are portable, on-site testers on the market that test the pull-out strength of roofing fasteners such as nails and screws. There are also testers considered portable that can measure the deflection, or compression distance, of materials such as foam used in bedding. Another portable tester can be mounted to roof supports and measure the force it takes to deflect the roof membrane material.
Some of these representative testers are disclosed in U.S. Pat. Nos. 4,753,115; 3,942,368; 3,563,087; 4,662,227; 4,004,457; and 5,067,353. The disclosures of which are hereby incorporated by reference herein. While all of the testers listed above can provide for portable testing of construction building materials, none can test for the compressive yield strength of spray roof foam or foam building materials on-site at the point of application.
Therefore, it is the object of this invention to provide a method of testing for the compressive yield stress of spray roof foam of foam building materials.
Another object of the invention is to provide a compression foam tester that is portable and can be used on-site at the point of application.
Another object of the invention is to provide a compression foam tester that is simple to set-up and easy to use.
Another object of the invention is to provide a compression foam tester that can be used in conjunction with, and adapted to, the many portable construction fastener testers on the market.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure. Accordingly, other objects and a more comprehensive understanding of the invention may be obtained by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.